Ectopic Pregnancy?

Hi everyone. I've been nauseated, experiencing full breasts and urinating frequently for 2 almost 3 weeks. I took a pregnancy test and it was negative and I thought maybe I tested too soon. Well, Monday I start having other symptoms like, shoulder pain, left lower pelvic area pain, light bright red spotting,chills,dizziness, and cramping. Went to ER and they only did a urinalysis and said oh you're not pregnant it's just menstrual cramps. I know that's not true bc I never experienced anything like this before. Today I'm currently having the same symptoms with added neck pain. Can anyone give me any insight as to what maybe going on? And can you have an ectopic pregnancy with a negative test result? Thanks in advance!!!